Search Technical Articles:
Product Categories
Search Help
  Welcome to our website!
Welcome! Now:  
Other Technical Articles
· Multi-Layer Injection Molded Tubs
( 2011-09-01 )
· Microcellular Foam Molds 'Impossible' Parts
( 2011-08-19 )
· Reasons Why Non-Return Valves Leak
( 2011-08-05 )
· Nylon Compound Aims Metal in Cars
( 2011-07-21 )
· Nanolayers Come to Tubing
( 2011-07-05 )
· A Legacy Built on Automation
( 2011-06-21 )
· New Hydraulic Press Saves Energy by up to 40%
( 2011-06-15 )
· How to Manage Multiple Heads
( 2011-06-08 )
· How to Choose the Right Pelletizer
( 2011-05-27 )
· Things to Look for in a Conveyor System
( 2011-05-18 )
· Making a Part for the First Time?
( 2011-04-27 )
· Create a Maintenance Work (Bench) Cell
( 2011-04-18 )
· Pay Attention to Your Nozzle Body & Tip
( 2011-04-08 )
· How to Set Second-Stage Pressure
( 2011-03-29 )
· Electric Machines Starting to buzz
( 2011-03-21 )
· Five-Layer Film Structures Set to Supplant Three Layers?
( 2011-03-10 )
· Downgauge Film While Sustaining Quality
( 2011-02-16 )
· Geothermal Cooling Works in Molding, Too
( 2011-02-11 )
· The Function of Extrusion Equipment and Energy Control During...
( 2009-02-20 )
· New extruder twin-screw feeder design
( 2009-02-18 )
Technical Articles
Home >> Technical Articles >>What's the Extruder and Extrusion
What's the Extruder and Extrusion
Time: 2008-12-19
Single screw extruders are the most common type of screw extruder. Single screw extruders use a single screw in combination with a cylinder or barrel for providing the mixing and conveyance through the extruder die plate at the end other end of the extruder to form the final product shape. There a numerous combination of screws and barrels to provide the necessary mixing, texturizing and kneading of the product to make it suitable for shaping through a die plate and sized to a required length.
Stokes flow through a single-screw extruder driven either by an axial pressure-gradient, or by the rotation of the screw, or by a combination of both is analyzed. The geometry of the screw is chosen to resemble that encountered in the metering section of a real-life industrial extruder. Working on the simplifying assumption of large helical pitch, a perturbation analysis is performed in non-orthogonal helical coordinates, and contributions to the velocity and pressure fields are computed up to second-order by finite element methods for unidirectional and two-dimensional Stokes flow. Velocity fields are presented for different screw geometries, the axial flow rate is computed for pressure- and rotation-driven flow, comparisons with simple models are made, and the effect of the pitch on the trajectories of passively convected particles is demonstrated. In the case of purely pressure-driven flow, the flow rate decreases, whereas in the case of rotating flow the flow rate increases as the gap between the screw and the barrel is reduced.
Browse Alphabetically :blow molding machine
Copyright © 2008 All rights reserved.